Title: Crystal structure of a secreted lipase from Gibberella zeae reveals a novel double-lock mechanism Lou Z, Li M, Sun Y, Liu Y, Liu Z, Wu W, Rao Z Ref: Protein Cell, 1:760, 2010 : PubMed
Fusarium graminearum (sexual stage: Gibberella zeae) is the causative agent of Fusarium Head Blight (FHB), which is one of the most destructive plant disease of cereals, accounting for high grain yield losses, especially for wheat and maize. Like other fungal pathogens, several extracellular enzymes secreted by G. zeae are known to be involved in host infection. Among these secreted lipases, G. zeae lipase (GZEL), which is encoded by the FGL1 gene, was demonstrated to be crucial to G. zeae pathogenicity. However, the precise mechanism of GZEL remains unclear due to a lack of detailed structural information. In this study, we report the crystal structure of GZEL at the atomic level. The structure of GZEL displays distinct structural differences compared to reported homologues and indicates a unique "double lock" enzymatic mechanism. To gain insight into substrate/inhibitor recognition, we proposed a model of GZEL in complex with substrate and the lipase inhibitor ebelactone B (based on the reported structures of GZEL homologues), which defines possible substrate binding sites within the catalytic cleft and suggests an "anti sn-l" binding mode. These results pave the way to elucidating the mechanism of GZEL and thus provide clues for the design of anti-FHB inhibitors.
        
Title: Crystallization and preliminary crystallographic analysis of Gibberella zeae extracellular lipase Sun Y, Li M, Zhang Y, Liu L, Liu Y, Liu Z, Li X, Lou Z Ref: Acta Crystallographica Sect F Struct Biol Cryst Commun, 64:813, 2008 : PubMed
Fusarium head blight, one of the most destructive crop diseases, is mainly caused by Fusarium graminearum (known in its sexual stage as Gibberella zeae). F. graminearum secretes various extracellular enzymes that have been hypothesized to be involved in host infection. One of the extracellular enzymes secreted by this organism is the G. zeae extracellular lipase (GZEL), which is encoded by the FGL1 gene. In order to solve the crystal structure of GZEL and to gain a better understanding of the biological functions of the protein and of possible inhibitory mechanisms of lipase inhibitors, recombinant GZEL was crystallized at 291 K using PEG 3350 as a precipitant. A data set was collected to 2.8 A resolution from a single flash-cooled crystal (100 K). The crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 78.4, b = 91.0, c = 195.8 A, alpha = beta = gamma = 90 degrees . The presence of four molecules was assumed per asymmetric unit, which gave a Matthews coefficient of 2.6 A(3) Da(-1).
        
Representative scheme of Lipase_3 structure and an image from PDBsum server
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